Checklists of the World's Birds
There is no point in putting checklists of birds on Ornithology Education. There are plenty online already. You can go to Avibase, Clement's Checklist from Cornell, HBW and BirdLife International Illustrated Checklist of the Birds of the World, The Sibley-Monroe Checklist, The Howard and Moore Complete Checklist of Birds of the World, and Wikipedia checklists for each of the 192 countries of the world. You can read more detail on each of these birdlists at Birding Ecotours.
Sometimes the country itself puts out a checklist or the Audubon Society or some other bird-oriented organization of that country does, but I find Wikipedia to be the fastest way to check out what birds are where. Although I can't vouch for the accuracy of Wikipidia's checklists, I'll just say I haven't found many errors.
There are also checklists of birds by region, province or state and some birding tour operators provide checklists to entice you to travel with them.
The bird species in a checklist are placed in phylogenetic order, which means that the first bird on the list is a species that has evolved the earliest and the last bird species is one which has arisen the latest.
The number of species on a checklist depends on the region covered by that checklist. A small city may have a checklist with less than 200 species whereas a natural area which is a significant site for birds may have up to 400 species. Generally, the further north or south you are from the equator, the fewer species you will encounter, due to decreasing diversity of birds with an increase in latitude from the tropics to the polar regions.
The four checklists with links above out of a current total 11,524 extant and recently extinct species, the four lists agree on 9,968 (86.5%) of them, leaving 1556 species questionable and I suspect as these questions are answered, more will arise. Avian taxonomy is, fortunately or unfortunately, a dynamic process. The most frequent disagreements were of birds from the southeast Asia, Australian, and south polar regions because these birds are the least studied and in an area with many islands, leading to extensive diversification.
If you want to keep a checklist of all your ebird sightings, consider Scythebill.